Retzius-sparing robot-assisted radical prostatectomy vs the standard approach: a systematic review and analysis of comparative outcomes

Objectives: To summarize the current evidence on Retzius-sparing (RS)-robot-assisted radical prostatectomy (RARP) and to compare its oncological, peri-operative and functional outcomes with those of standard retropubic RARP (S-RARP). Materials and Methods: After establishing an a priori protocol, a systematic electronic literature search was conducted in January 2019 using the Medline (via PubMed), Embase (via Ovid) and Cochrane databases. The search strategy relied on the ‘PICO‘ (Patient Intervention Comparison Outcome) criteria and article selection was carried out in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Only studies reporting the oncological and functional outcomes of RARP (as determined by type of procedure [RS-RARP vs S-RARP]) were considered for inclusion. Risk of bias and study quality were assessed. Finally, peri-operative and functional outcomes were recorded and analysed. Results: A shorter operating time was associated with RS-RARP (weighted mean difference [WMD] 14.7 min, 95% confidence interval [CI] −28.25, 1.16; P = 0.03), whereas no significant difference was found in terms of estimated blood loss (WMD 1.45 mL, 95% CI −31.18, 34.08; P = 0.93). Also, no significant difference between the two groups was observed for overall (odds ratio [OR] 0.86, 95% CI 0.40, 1.85; P = 0.71) and major (Clavien >3; OR 0.88, 95% CI 0.30, 2.57) postoperative complications; however, the likelihood of positive surgical margins (PSMs) was lower for the S-RARP group (rate 15.2% vs 24%; OR 1.71, 95% CI 1.12, 2.60; P = 0.01). The cumulative analysis showed a statistically significant advantage for RS-RARP in terms of continence recovery at 1 month (OR 2.54, 95% CI 1.16, 5.53; P = 0.02), as well as at 3 months (OR 3.86, 95% CI 2.23, 6.68; P < 0.001), 6 months (OR 3.61, 95% CI 1.88, 6.91; P = 0.001), and 12 months (OR 7.29, 95% CI 1.89, 28.13; P = 0.004). Conclusion: Our analysis confirms that RS-RARP is a safe and feasible alternative to S-RARP. This novel approach may be associated with faster and higher recovery of continence, without increasing the risk of complications. One caveat might be the higher risk of PSMs, and this can be regarded as a current pitfall of the technique, probably related to an expected learning curve.